/* 
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed  under the  License is distributed on an "AS IS" BASIS,
 * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
 * implied.
 * 
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.cli.avalon;

// Renamed from org.apache.avalon.excalibur.cli

/**
 * CLUtil offers basic utility operations for use both internal and external to
 * package.
 * 
 * @see CLOptionDescriptor
 */
public final class CLUtil {
	private static final int MAX_DESCRIPTION_COLUMN_LENGTH = 60;

	/**
	 * Private Constructor so that no instance can ever be created.
	 * 
	 */
	private CLUtil() {
	}

	/**
	 * Format options into StringBuffer and return. This is typically used to
	 * print "Usage" text in response to a "--help" or invalid option.
	 * 
	 * @param options
	 *            the option descriptors
	 * @return the formatted description/help for options
	 */
	public static final StringBuffer describeOptions(final CLOptionDescriptor[] options) {
		final String lSep = System.getProperty("line.separator");
		final StringBuffer sb = new StringBuffer();

		for (int i = 0; i < options.length; i++) {
			final char ch = (char) options[i].getId();
			final String name = options[i].getName();
			String description = options[i].getDescription();
			int flags = options[i].getFlags();
			boolean argumentOptional = ((flags & CLOptionDescriptor.ARGUMENT_OPTIONAL) == CLOptionDescriptor.ARGUMENT_OPTIONAL);
			boolean argumentRequired = ((flags & CLOptionDescriptor.ARGUMENT_REQUIRED) == CLOptionDescriptor.ARGUMENT_REQUIRED);
			boolean twoArgumentsRequired = ((flags & CLOptionDescriptor.ARGUMENTS_REQUIRED_2) == CLOptionDescriptor.ARGUMENTS_REQUIRED_2);
			boolean needComma = false;
			if (twoArgumentsRequired) {
				argumentRequired = true;
			}

			sb.append('\t');

			if (Character.isLetter(ch)) {
				sb.append("-");
				sb.append(ch);
				needComma = true;
			}

			if (null != name) {
				if (needComma) {
					sb.append(", ");
				}

				sb.append("--");
				sb.append(name);
			}

			if (argumentOptional) {
				sb.append(" [<argument>]");
			}
			if (argumentRequired) {
				sb.append(" <argument>");
			}
			if (twoArgumentsRequired) {
				sb.append("=<value>");
			}
			sb.append(lSep);

			if (null != description) {
				while (description.length() > MAX_DESCRIPTION_COLUMN_LENGTH) {
					final String descriptionPart = description.substring(0, MAX_DESCRIPTION_COLUMN_LENGTH);
					description = description.substring(MAX_DESCRIPTION_COLUMN_LENGTH);
					sb.append("\t\t");
					sb.append(descriptionPart);
					sb.append(lSep);
				}

				sb.append("\t\t");
				sb.append(description);
				sb.append(lSep);
			}
		}
		return sb;
	}
}
